This invention relates to a robot type welding apparatus which is chiefly used, in the fabricating of a car body of a motorcar, to apply spot welding to a peripheral edge of an opening portion of the car body such as that of a door attaching portion or the like.
As to an apparatus of this kind, providing a welding gun on a wrist mechanism on a front end portion of a supporting arm extending from main body of a robot is known. This type of apparatus, however, is inconvenient in that, for making the welding gun cable freely to any part of the whole peripheral edge of the foregoing opening portion, it is necessary that the supporting arm and the wrist mechanism be comparatively complicated in construction and that every moveable portion of them is given comparatively large movements. Thus, it cannot be avoided that the whole of the apparatus becomes comparatively large-sized and high priced.